Funding for this research was provided by:
Institut Pengurusan dan Pemantauan Penyelidikan, Universiti Malaya (UMRG, RP031-14HTM)
Postgraduate Research Fund PPPC (PPPC/C1-2015/DGL/22, PG025-2014A)
Received: 1 November 2019
Accepted: 6 February 2020
First Online: 14 February 2020
Ethics approval and consent to participate
: This study was approved by the Medical Ethical Committee, Faculty of Dentistry University of Malaya following the guidelines of the Declaration of Helsinki and Tokyo for humans (DF PE1501/0085(L)). Written informed consents were obtained from all eligible participants prior to the beginning of the study.
: Not Applicable.
: The authors declare that they have no competing interests.